public static ClassroomExamBlModel GetBlModel(this ClassroomExam item)
        {
            var blItem = new ClassroomExamBlModel()
            {
                Classroom   = item.Classroom?.GetBlModel(),
                ClassroomId = item.ClassroomId
            };

            return(blItem);
        }
        public static ClassroomExam GetDataModel(this ClassroomExamBlModel item)
        {
            var blItem = new ClassroomExam()
            {
                Classroom   = item.Classroom?.GetDataModel(),
                ClassroomId = item.ClassroomId,
                Exam        = item.Exam?.GetDataModel(),
                ExamId      = item.ExamId
            };

            return(blItem);
        }